Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Goes well past the readOnlyHint/idempotentHint annotations: it declares the 30-day lookback window, that credential fields are returned as names only and never in plaintext, and that missing SERP/Gemini/Perplexity adapters report account, vault access and cost/request limits rather than silently omitting them. The explicit read-only guarantee reinforces rather than contradicts the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the resource list and ends with the read-only constraint, which is the right ordering. Four dense sentences are justified for a composite zero-param audit tool, though the third sentence's three-adapter enumeration is the most expendable part.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, so the description carries the full burden of describing return values — and it does: field names surfaced, plaintext exclusion, confirmed Search Console property, separately approved reports, and how missing adapters are represented. An agent knows what it will get before calling.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description correctly spends its words on output content instead of inventing parameter guidance.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (liest) plus a concrete inventory of what is returned: connections, Google Ads conversion actions, 30-day activity, upload receipts, setup paths, Search Console property, OpenAI reports. That scope (a composite setup overview) implicitly separates it from single-domain siblings like get_advertising_performance, but no sibling is named, so it stops short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Closes with an explicit exclusion list — no OAuth start, no paid provider calls, no approvals, uploads or credential changes — which steers an agent toward the apply_* tools when a write is needed. It never explicitly says 'use tool X instead', so the routing is implied rather than stated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.